An alternator mounted on a vehicle is, in many cases, controlled in such a manner that a control current (field current) of the alternator is controlled to control a power generation amount for preventing the battery from being in lack of charge due to checking a charging state of the battery. (refer to JP-2000-4502A and JP-2001-78365A).
This alternator is driven by power of an internal combustion engine and therefore, at the time of power generation, additional fuel is to be consumed in accordance with a load required for driving the alternator. Therefore, some of the alternators generate power only in a region where fuel consumption at the time of the power generation is reduced (refer to JP-6-505619T and JP-2005-12971A).
Although the technology described in JP-6-505619T or JP-2005-12971A each is to reduce an increment of the fuel consumption due to the power generation, an operating condition in which the power generation is carried out is determined by a map in advance set. Accordingly, the fuel saving effect easily depends on accuracy of the map, use environments of a vehicle (a difference in travel road state, a difference in vehicle speed and a difference in acceleration/deceleration by a driver, or the like) or variations in vehicle characteristic. Therefore, the above technology does not necessarily obtain a sufficient fuel saving effect.
In view of the above, there exists a need for a power generation control apparatus for an internal combustion engine which overcomes the above mentioned problems in the conventional art. The present invention addresses this need in the conventional art as well as other needs, which will become apparent to those skilled in the art from this disclosure.